1. Field of the Invention
The present invention relates to a lubricating structure of a transmission which supplies a lubricating oil from an input shaft within the transmission.
2. Description of the Related Art
There has conventionally been known a lubricating structure adapted to supply a lubricating oil, in a structure in which an input member side of a clutch having the input member and an output member is fixed to an input shaft in a transmission, to a canceller chamber and a clutch plate of the clutch, via an oil passage within the input shaft. For example, in Japanese Patent Laid-Open No. 2001-50301, a structure in which the lubricating oil is supplied to the canceller chamber of the clutch via the oil passage provided in the input shaft, and a hydraulic oil of the clutch is supplied via another oil passage provided to the input shaft, is disclosed.
Further, the oil passage inside the input shaft for supplying the lubricating oil to the clutch is used for supplying the lubricating oil via a lubrication hole provided in the input shaft, also to members arranged around the input shaft. The members arranged around the input shaft includes, for example, a transmission mechanism such as a bearing which rotatably supports a gear and the like about the input shaft, its gear, and a synchromesh mechanism and the like.
However, in the case where the lubricating oil is supplied via the oil passage in the input shaft to the mechanism existing around the input shaft halfway of the oil passage, and to the clutch positioned near the terminal end thereof, a distribution amount of the lubricating oil distributed via lubrication holes provided to the positions corresponding thereto varies upon receiving influence of a revolving speed of the input shaft.
That is, in the case where the revolving speed is fast, large amount of lubricating oil flows out from the lubrication hole on an upstream side, and in the case where the revolving speed is slow, an opposite phenomenon occurs. Therefore, the supply amount of the lubricating oil with respect to the clutch varies by the revolving speed of the input shaft, so that a problem that the stable supply of the lubricating oil to the clutch is impaired, or a filling of the lubricating oil into the canceller chamber is delayed, occurs.
In order to avoid this, it is conceivable to supply the lubricating oil from an end portion on the side where the clutch exists to the oil passage of the input shaft. However, in the case where a hydraulic pump for supplying the lubricating oil is provided on a side opposite to the clutch of the transmission, it becomes necessary to separately provide a long oil passage from the hydraulic pump to a case portion near the end portion of the input shaft on the clutch side, leading to increase in the length or weight of the transmission.